Over the past seven years, city officials, teachers and attorneys for special-education students have repeatedly alerted D.C. Public Schools to cases of student suspensions that were not properly documented. And yet the problem has persisted.

The Washington Post reported last week that in 2016 and 2017, several DCPS high schools barred students from class without recording them as suspended. In response, DCPS officials said they would examine data for those schools but were confident that others were following the rules.

School officials also told The Post that they quickly address any allegations of such unreported suspensions. But critics question the diligence with which the school system has moved to address informal — and thus hidden — suspensions, even as it boasted a 40 percent decline in suspensions from 2014 to 2016.

Some teachers and discipline-change advocates say that principals have sent children home without documentation because the principals’ evaluations depend in part on reducing suspensions. They also say that central office officials have turned a blind eye because the officials are also under pressure to show progress.

“It’s concerning that in DCPS there are people in school buildings who are doing very destructive things for students, and central office doesn’t seem to take a stance,” said Patrice Wedderburn, a lawyer who represents a student repeatedly suspended in the last school year without proper documentation. “DCPS has made a lot of sacrifices to try to achieve some very narrow gains, and it has come at the expense of children and families.”

Schools Chancellor Antwan Wilson said Monday that he has asked for an independent audit “to look further into this issue.”

“We want all students to be in school every day, and to use suspensions only when absolutely necessary,” Wilson said in a statement. “I am proud of schools who have embraced restorative practices, and the nearly 40 percent reduction in suspensions that we have seen.”

In the past two years, at least seven high schools sent daily messages to staff listing students who had misbehaved and were not permitted to enter the building, according to emails The Post obtained under the Freedom of Information Act (FOIA).

But attendance records show that a small fraction were recorded as suspensions. Some students barred from school were marked as present, while others were marked as attending an “in-school activity” or absent without an excuse.

The Post limited its query to high schools to expedite the FOIA request. Asked about the findings, school officials initially said they saw no reason for a broader look at all 115 D.C. system schools.

Then, in an apparent reversal, school officials told The Post’s editorial board on Friday that they intend to conduct a “complete audit.” On Monday, they declined to share details about the extent of that audit.

DCPS officials knew students were being sent home without documentation at least as early as 2010, according to documents The Post obtained.

That year, a complaint registered with the D.C. Office of the State Superintendent of Education (OSSE) — which oversees compliance with special-ed law — alleged that a student had been “informally” suspended, or sent home, without record of a suspension.

Tameria J. Lewis, head of OSSE’s special-education division at the time, substantiated that complaint, finding that DCPS had failed to keep accurate discipline and attendance records.

On Dec. 30, 2010, Lewis wrote to DCPS that issuing “informal” suspensions to students with disabilities “blatantly disregards” protections they are afforded under federal law. She ordered DCPS to “immediately cease” informal suspensions, and she gave DCPS officials a deadline of April 29, 2011, to tell all schools that they must accurately track attendance and suspensions. An OSSE spokeswoman said Monday that DCPS complied with the order.

But the problem did not stop. In 2012 and 2013, OSSE substantiated similar complaints from special-education students who said they had been repeatedly sent home without being suspended. In both cases, OSSE told DCPS the schools involved must accurately track suspensions.

Repeatedly sending a child home is “unacceptable” because the student is likely to miss educational services to which they are entitled, Amy Maisterra, then OSSE’s head of special education, wrote to DCPS in 2013. She added: “The school must immediately cease the practice of informal, undocumented release or dismissal of students from school.”

OSSE’s letters do not identify the schools involved to protect the privacy of the students.

Maria Blaeuer, a special-education lawyer, said that since 2010 she has settled multiple due-process complaints with DCPS on behalf of students informally suspended from Kelly Miller Middle School.

“To have central office know that this is happening — be aware of it, resolve cases and not doing anything about it — was profoundly disappointing to me,” Blaeuer said.

DCPS touted Kelly Miller — a Ward 7 school that serves primarily black and disadvantaged students — as a turnaround success under the leadership of Abdullah Zaki II, who was named principal of the year in 2013. Under Zaki, test scores rose, truancy dropped from 30 percent to 1 percent, and suspensions fell by more than half, according to his citation for the award.

Jason Harrison, who taught history at Kelly Miller in 2013-2014, suspected the numbers weren’t accurate. In July 2014, he shared his concern with a senior DCPS official: Jason Kamras, then chief of human capital.

In an email to Kamras, Harrison wrote that Kelly Miller administrators instructed teachers not to take attendance on days when absences were traditionally high, such as before holidays or when the weather was particularly bad.

In addition, Harrison wrote, students were often told that they couldn’t return to school without a parent, “or they were quietly told not to come to school and were given ‘work packets.’ ”

“It’s possible that there may have been documentation on those students who were told they couldn’t return without a parent. But I don’t think anything official was ever submitted about those students encouraged not to come to school,” Harrison wrote.

Kamras thanked Harrison for his note. “I assure you we will explore this,” Kamras wrote the teacher in August 2014.

Kamras, who is now chief of instructional practice for DCPS, did not respond to email and voice messages on Monday. Officials said he was on vacation.

In 2015, Zaki was named principal of Dunbar High. Once a top-flight public prep school for black students during the days of legal segregation, it continues to enroll almost exclusively black students. Many come from low-income families and struggle with chronic truancy and low academic performance.

Dunbar underreported suspensions to a greater degree than any other high school in January 2017, The Post found. Just 7 percent of the days that its students were kept out of class for misbehavior were actually reported as suspensions, according to data The Post obtained.

OSSE is investigating a complaint about Dunbar’s use of undocumented suspensions, according to Wedderburn, the lawyer representing a student repeatedly suspended without documentation last year.

Johnnie Walker served as Dunbar’s attendance counselor until the end of the 2015-16 school ­year. He said he repeatedly clashed ­with Zaki over unreported suspensions.

“They just did away with documentation and arbitrarily sent the kid home,” Walker said. Students sent home were often marked “unexcused absent” instead of “suspended,” Walker said. When they reached 15 unexcused absences, he was supposed to refer them to truancy court — but he refused, he said, because he didn’t think it was right.

Zaki referred a request for comment to the DCPS communications office, which did not address questions about attendance and suspensions during his tenure at Dunbar and Kelly Miller.